City with most 50 home run seasons: New York!

Ten players seasons, 9 years, six players, two teams.

Rk	Player	Year	HR	Age	Tm	Lg	G	PA	AB	R	H	2B	3B	RBI	BB	IBB	SO	HBP	SH	SF	GDP	SB	CS	BA	OBP	SLG	OPS	Pos
1	Babe Ruth	1920	54	25	NYY	AL	142	616	458	158	172	36	9	135	150		80	3	5			14	14	.376	.532	.847	1.379	*978/3H1
2	Babe Ruth	1921	59	26	NYY	AL	152	693	540	177	204	44	16	168	145		81	4	4			17	13	.378	.512	.846	1.359	*78/13
3	Babe Ruth	1927	60	32	NYY	AL	151	691	540	158	192	29	8	165	137		89	0	14			7	6	.356	.486	.772	1.258	*97
4	Babe Ruth	1928	54	33	NYY	AL	154	684	536	163	173	29	8	146	137		87	3	8			4	5	.323	.463	.709	1.172	*97
5	Mickey Mantle	1956	52	24	NYY	AL	150	652	533	132	188	22	5	130	112	6	99	2	1	4	4	10	1	.353	.464	.705	1.169	*8/H
6	Mickey Mantle	1961	54	29	NYY	AL	153	646	514	131	163	16	6	128	126	9	112	0	1	5	2	12	1	.317	.448	.687	1.135	*8/H
7	Roger Maris	1961	61	26	NYY	AL	161	698	590	132	159	16	4	141	94	0	67	7	0	7	16	0	0	.269	.372	.620	.993	*98/H
8	Alex Rodriguez	2007	54	31	NYY	AL	158	708	583	143	183	31	0	156	95	11	120	21	0	9	15	24	4	.314	.422	.645	1.067	*5/D

Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 8/12/2015.

Rk	Player	Year	HR	Age	Tm	Lg	G	PA	AB	R	H	2B	3B	RBI	BB	IBB	SO	HBP	SH	SF	GDP	SB	CS	BA	OBP	SLG	OPS	Pos
1	Johnny Mize	1947	51	34	NYG	NL	154	664	586	137	177	26	2	138	74		42	4	0		6	2		.302	.384	.614	.998	*3
2	Willie Mays	1955	51	24	NYG	NL	152	670	580	123	185	18	13	127	79	13	60	4	0	7	12	24	4	.319	.400	.659	1.059	*8

Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 8/12/2015.

Ten years later playing his home games in San Francisco Mays, the all time Giant, would hit 52.

No 50 homer seasons for the Brooklyn Dodgers (nor for the LA Dodgers either) or the New York Mets.  No other city is close.

Ironically, Ruth in all four and Mantle in 1961 led the league in BB.  All but Mantle in 1961 led in homers.

Johnny Mize,.Baseball Digest inside front cover, March 1948 via Wikimedia Commons

The two Giants had by far the fewest BB but also the fewest SO.  Mize is the only 50 HR hitter on any team with fewer SO than HR: 42 to 51.

Ruth led the league in SO twice.  Only Maris had a BA lower than .300.  Ruth was the only one with fewer than 500 AB; Maris had the most AB followed by the two Giants.

Eight of the nine years led the league in Runs and Home Runs; 7 of 9 RBI.

Ruth had 204 hits in 1921.

Maris will never be elected to the Hall of Fame.  Except for the active Rodriguez, all the others are in the Hall.  Yes, Rodriguez used PED and may never be elected.